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Development and fabrication of graphene Hall probes
Supalová, Linda ; Červenka, Jiří (referee) ; Bartošík, Miroslav (advisor)
Pokrok v inženýrství a technologiích vytvořil zájem o stabilní detektory magnetického pole schopné operovat v širokém rozsahu teplot. Senzory založené na Hallově jevu a obří magnetorezistenci jsou nejčastěji využívaná zařízení k neinvazivnímu měření statických i dynamických magnetických polí v reálném čase. Aplikace zařízení na bázi Hallova jevu zahrnují například lineární senzory magnetického pole, gyrátory, rychlostní a směrové senzory, elektrické kompasy a senzory proudu, v oblastech sahajících od výroby, automobilového a kosmického průmyslu po komunikační systémy. Nicméně současné materiály využívané v Hallových sondách (především III-V polovodiče jako InSb nebo GaAs) mají potíže s teplotní stabilitou. V této práci se zabýváme výrobou Hallových sond založených na grafénu a jejich testováním za zvýšených teplot. Úspěšně jsme vyrobili grafénové Hallovy sondy v uspořádání polem řízeného tranzistoru pomocí standartních výrobních metod jako litografie a depozice tenkých vrstev. Volba uspořádání polem řízeného tranzistoru nám umožňuje naplno využít vynikajících elektrických vlastností grafénu při testování těchto Hallových sond v rozmezí od pokojové teploty až do 200°C. Naše výsledky ukazují, že zvyšování teploty nezpůsobuje zásadní zhoršení výkonnosti grafénových Hallových sond i při teplotách nad 150°C. Tato práce otevírá dveře pro další výzkum chování grafénových Hallových sond za zvýšené teploty s důrazem na porozumění externích faktorů, které ovlivňují výkonnost takového senzoru při využití v normálních podmínkách.
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Gaussmeter With A Three-Axis Probe
Hejtmánek, Tomáš
The purpose of this article is the design of a gaussmeter with a three-axis probe for magnetic field mapping and subsequent reconstruction of the image using magnetic impedance tomography (MIT). Commercially available gaussmeters have low bandwidth for these purposes, and signals cannot be measured in synchronous detection mode. The aim of the paper is select the most suitable magnetic field sensors for the MIT purposes and to design the entire measuring device to meet the measurement requirements in the wider frequency band and synchronous detection.
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Gaussmeter design with three-axis measuring probe
Hejtmánek, Tomáš ; Novák,, Miroslav (referee) ; Roubal, Zdeněk (advisor)
The purpose of this work is the design of a gaussmeter with a three-axis probe for magnetic field mapping and subsequent reconstruction of the image using magnetic impedance tomography. Commercially available gaussmeters have low bandwidth for these purposes, and signals cannot be measured in synchronous detection mode. The aim of the thesis is select the most suitable magnetic field sensors for the MIT purposes and to design the entire measuring device to meet the measurement requirements in the wider frequency band and synchronous detection. Attention will also be paid to designing a suitable mechanical design of the probe and the location of the sensors. The proposed device will be tested and evaluated for MIT purposes.
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Design of a convertor for a BLDC motor
Stejskal, Martin ; Valach, Soběslav (referee) ; Macho, Tomáš (advisor)
This master thesis deals with the design and realization of a drive for a 500 W BLDC motor powered with a battery power supply. It also deals with the possibilities of realization of drives and other possibilities to control these motors. Describes the implementation of the inverter using Atmel's AVR microcontroller. The thesis also deals with the design of an auxiliary switching inverter. Communication with UART and CAN interface is also implemented.
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BLDC drive control
Havlíček, Jiří ; Buchta, Luděk (referee) ; Otava, Lukáš (advisor)
The bachelor thesis is focused on problems of sensor control of Brushless DC Electric motor (BLDC) using hall-effect sensors. The BLDC motor is connected to 3-Phase low-voltage board which was produced by Freescale Semiconductor, Inc. The board is adapted to control electrical motors by MC56F8006 signal microcontroller. The next part is devoted to implementation of interconnection of the machine with the Matlab/Simulink programme using the MF 624 multifunction I/O card. Cascaded control, current and speed loops are used for the final configuration. The former loop is realized in the signal microcontroller, the latter one in the Simulink programme.
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Wind tunnel model with universal inputs and outputs
Holčík, Martin ; Kaczmarczyk, Václav (referee) ; Štohl, Radek (advisor)
The aim of this work is to design and implement a model of wind tunnel. The model can be controlled in various ranges of standardized signals in both analog and digital form. The model consists two fans - an electrically driven fan and fan driven by air stream. The outputs from the model are standardized signals, carrying information about the speed of second fan. The following document discusses the design of components, and subsequent implementation of the technical problems that occurred, a description of the final solution and the software part of the solution.
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Application for magnetic field mapping using F.W.BELL 9950
Kohnheiser, Jan ; Kubásek, Radek (referee) ; Hadinec, Michal (advisor)
The aim of this project is to acquaint the reader with the possibilities of controlling gaussmeter FW Bell 9950 by computer. The thesis analyzes the problems of measurement of magnetic flux density and the measuring instrument itself and its ability to communicate with the PC will be introduced. Next part of the thesis deals with the description and control of the application designed for communication and mapping magnetic field with F.W. Bell 9950.
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Compact inverter for BLDC motor
Nevřivý, Tomáš ; Červinka, Dalibor (referee) ; Procházka, Petr (advisor)
The work describes the design and implementation of compact inverter for brushless DC motor, which have mechanical power 600 W and rated torque 1.6 Nm. Motor is designed for DC link voltage with value 300 V. The focus is placed on the cost and simplicity. On this basis, the inverter is designed for uses single purpose power and control circuit. The power part is solved using a circuit FSBB15CH60C. The circuit is placed on a separate board of power electronics. Cooling of the power circuit is performed by the surface structure of BLDC motor. Control of the inverter ensures circuits LB11696V and NE566. The both circuits are placed on separate board of control electronics. Circuit LB11696V contains a control algorithm, as well as protections, which are necessary for safe operation of the inverter. Power supply of electronics is performed using step-down converter from MYRRA company.
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Drive model for EC motor elevator analysis
Javořík, Zdeněk ; Koláčný, Josef (referee) ; Vondruš, Jiří (advisor)
The master thesis encompasses the possibilities of position evaluation and drive control with the aid of SMI work enviroment. Furthermore the thesis is directed to create a program through a designed control algorithm. The work is realised on the elevator model with electronically commuted motor. An incremental scanner is used as the position sensor. The motor control unit is set up and programmed in the SmartMotorInterface software. In the next part, measurements with altered parameters are conducted. On the basis of these measurements the influence of parameters on the positioning process and its accuracy is evaluated. At the conclusion of the work, a design of laboratory task for educational purposes is created. The laboratory task is composed in such a way, that students would become familiar with the SMI work enviroment and would be able to practicaly test the setup of incremental position sensor and motor control with the aid of entered algorithm.
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